JP7064897B2 - Method for producing unsaturated hydrocarbons - Google Patents

Description

The present invention relates to a method for producing unsaturated hydrocarbons.

Unsaturated hydrocarbons obtained by the dehydrogenation reaction of alkanes are required in large quantities in various fields, for example, as starting materials for industrial products. For example, unsaturated hydrocarbons are used in the production of detergents, high octane gasoline, chemicals and the like, as well as in the production of plastics and the like.

In particular, butene is widely used as a starting material for methyl ethyl ketone, alkylate gasoline and the like. As a method for producing butene, for example, a method of directly dehydrogenating n-butane using a non-uniform dehydrogenation catalyst is known (for example, Patent Documents 1 to 4).

Japanese Unexamined Patent Publication No. 2014-205135 Japanese Unexamined Patent Publication No. 2015-0276669 US Patent Application Publication No. 2014/0309470 US Pat. No. 6,433,241

With the increasing demand for unsaturated hydrocarbons, it is required to develop various alkane dehydrogenation methods having different characteristics such as required characteristics of manufacturing equipment, operating cost, and reaction efficiency.

An object of the present invention is to provide a method for producing an unsaturated hydrocarbon capable of efficiently converting an alkane as a new method for producing an unsaturated hydrocarbon.

The present inventors have found that an alkane can be efficiently dehydrogenated by a dehydrogenation catalyst having a specific carrier, a specific carrier metal, and a specific acid amount, and complete the present invention. I arrived.

One aspect of the present invention is a dehydrogenation step in which a raw material gas containing an alkane and steam is brought into contact with a dehydrogenation catalyst to obtain a product gas containing at least one unsaturated hydrocarbon selected from the group consisting of olefins and conjugated diene. The present invention relates to a method for producing an unsaturated hydrocarbon. In this production method, the dehydrogenation catalyst contains a carrier and a supported metal containing tin and platinum supported on the carrier, and is desorbed in the temperature range of 200 to 500 ° C. in the ammonia TPD method. The acid amount of the dehydrogenation catalyst defined by the amount of ammonia is 3.00 μmol / g or more.

In one embodiment, the acid content of the dehydrogenation catalyst may be 4.00 μmol / g or more.

In one embodiment, the carrier contains a first metal oxide containing a Group 4 element and a second metal oxide containing at least one selected from the group consisting of Group 2 elements and lanthanides. You may be.

In one embodiment, the first metal oxide may contain at least one selected from the group consisting of ZrO ₂ and HfO ₂ .

In one embodiment, the _second metal oxide may contain at _least one selected from the group consisting of CaO and La2O3.

In one embodiment, the content of the second metal oxide in the carrier may be 10% by mass or less based on the total amount of the carrier.

In one embodiment, the alkane may contain butane, the olefin may contain butene, and the conjugated diene may contain butadiene.

According to the present invention, as a new method for producing unsaturated hydrocarbons, there is provided a method for producing unsaturated hydrocarbons capable of efficiently converting alkanes.

Hereinafter, preferred embodiments of the present invention will be described.

The method for producing an unsaturated hydrocarbon according to the present embodiment comprises contacting a raw material gas containing an alkane and steam with a dehydrogenation catalyst to contain at least one unsaturated hydrocarbon selected from the group consisting of olefins and conjugated diene. It is equipped with a dehydrogenation step to obtain a generated gas.

In the present embodiment, the dehydrogenation catalyst contains a carrier and a supported metal including tin and platinum supported on the carrier. Further, the acid amount of the dehydrogenation catalyst defined by the amount of ammonia desorbed in the temperature range of 200 to 500 ° C. in the ammonia TPD method is 3.00 μmol / g or more.

According to the production method according to the present embodiment, alkanes can be dehydrogenated at a high conversion rate by using a dehydrogenation catalyst having a specific carrier, a specific carrier metal, and a specific acid amount. can.

The dehydrogenation catalyst used in the present embodiment is a solid catalyst that catalyzes the dehydrogenation reaction of alkane, and is a catalyst containing a carrier and a supported metal containing tin and platinum supported on the carrier. The carrier may be, for example, an inorganic oxide carrier.

In the ammonia TPD method, the acid amount of the dehydrogenation catalyst defined by the amount of ammonia desorbed in the temperature range of 200 to 500 ° C. is 3.00 μmol / g or more, more preferably 4.00 μmol / g or more. .. By using such a carrier, alkanes can be dehydrogenated at a high conversion rate. Further, the acid amount of the dehydrogenation catalyst defined by the amount of ammonia desorbed in the temperature range of 200 to 500 ° C. in the ammonia TPD method may be 15 μmol / g or less, and may be 10 μmol / g or less.

In the present specification, the acid amount of the catalyst indicates the amount of the acid point of the catalyst measured by the ammonia TPD method. The ammonia TPD method can be carried out, for example, under the equipment and measurement conditions described in "Niwa; Zeolites, 10,175 (1993)".

In a preferred embodiment, the carrier may be a carrier containing MgAl ₂ O ₄ having a spinel structure.

In another preferred embodiment, the carrier may be a carrier containing a first metal oxide containing a Group 4 element. Examples of the first metal oxide include TiO ₂ , ZrO ₂ and HfO ₂ . The first metal oxide preferably contains at least one selected from the group consisting of ZrO ₂ and HfO ₂ , and more preferably contains ZrO ₂ .

The content of the first metal oxide is preferably 80% by mass or more, more preferably 90% by mass or more, based on the total amount of the carrier. Further, the upper limit of the content of the first metal oxide is not particularly limited, and may be, for example, 99% by mass or less based on the total amount of the carrier. When the content of the first metal oxide is in the above range, the catalyst deterioration is more significantly suppressed, and the high activity tends to be maintained for a longer period of time.

In the above embodiment, the carrier may further contain a second metal oxide containing at least one selected from the group consisting of Group 2 elements and lanthanides.

Examples of the second metal oxide include MgO, CaO, SrO, BaO, La _{2O 3} and the like. Of the second metal oxides, CaO is preferable as the metal oxide containing a Group 2 element. Of the second metal oxides, La ₂ O ₃ is preferable as the metal oxide containing lanthanoids.

The content of the second metal oxide is preferably 20% by mass or less, more preferably 10% by mass or less, based on the total amount of the carrier. Further, the lower limit of the content of the second metal oxide is not particularly limited, and may be, for example, 1% by mass or more based on the total amount of the carrier. When the content of the second metal oxide is in the above range, the catalyst deterioration is more significantly suppressed, and the high activity tends to be maintained for a longer period of time.

The specific surface area of the carrier may be, for example, 30 m ² / g or more, preferably 50 m ² / g or more. This tends to further improve the conversion rate of alkanes. The specific surface area of the carrier may be, for example, 1000 m ² / g or less, preferably 500 m ² / g or less. This makes it possible to obtain a carrier having sufficient strength that can be suitably used industrially. In the present specification, the specific surface area of the carrier is measured by a BET specific surface area meter using a nitrogen adsorption method.

The amount of platinum (Pt) supported on the dehydrogenation catalyst may be, for example, 0.8% by mass or more, preferably 0.9% by mass or more, based on the total amount of the dehydrogenation catalyst. The amount of Pt supported may be, for example, 5.0% by mass or less, preferably 3.0% by mass or less, based on the total amount of the dehydrogenation catalyst. With such a loading amount, the Pt particles formed on the catalyst have a suitable size due to the dehydrogenation reaction, and the platinum surface area per unit platinum weight increases, so that a more efficient reaction system can be realized.

The amount of tin (Sn) supported on the dehydrogenation catalyst is, for example, 1.0% by mass or more, preferably 2.0% by mass or more, based on the total amount of the dehydrogenation catalyst. The amount of Sn supported is, for example, 5.0% by mass or less, preferably 3.0% by mass or less, based on the total amount of the dehydrogenation catalyst. When the amount of Sn supported is in the above range, not only the conversion rate of alkanes is more likely to be improved, but also catalyst deterioration is more significantly suppressed, and high activity tends to be maintained for a longer period of time.

The supported metal to be supported may be supported as an oxide or may be supported as a single metal.

The method for supporting the supported metal is not particularly limited, and examples thereof include an impregnation method, a deposition method, a coprecipitation method, a kneading method, an ion exchange method, and a pore filling method.

One aspect of the supporting method is shown below. First, the carrier is added to the solution containing the precursors of the supported metal (platinum source and tin source), and the carrier containing the solution is kneaded. Then, the solvent is removed by drying, and the obtained solid is calcined so that the supported metal can be supported on the carrier.

In the above-mentioned carrier method, the precursor of the carrier metal may be, for example, a metal salt or a complex. The metal salt of the supporting metal may be, for example, an inorganic salt, an organic acid salt, or a hydrate thereof. The inorganic salt may be, for example, a sulfate, a nitrate, a chloride, a phosphate, a carbonate or the like. The organic acid salt may be, for example, acetate, oxalate or the like. The carrier metal complex may be, for example, an alkoxide complex, an ammine complex, or the like.

The precursor of the supported metal is preferably a metal source containing no chlorine atom. By using a metal source containing no chlorine atom as the precursor, it is possible to prevent corrosion of the device during catalyst adjustment.

Firing can be performed, for example, in an air atmosphere or an oxygen atmosphere. The firing may be performed in one stage or in multiple stages of two or more stages. The firing temperature may be any temperature as long as it can decompose the precursor of the supported metal, and may be, for example, 200 to 1000 ° C. or 400 to 800 ° C. When performing multi-step firing, at least one step may be the firing temperature. The firing temperature at the other steps may be, for example, in the same range as described above, and may be 100 to 200 ° C.

The dehydrogenation catalyst may further contain a molding aid from the viewpoint of improving moldability. The molding aid may be, for example, a thickener, a surfactant, a water retaining material, a plasticizer, a binder raw material, or the like.

The shape of the dehydrogenation catalyst is not particularly limited, and may be, for example, a pellet shape, a granule shape, a honeycomb shape, a sponge shape, or the like.

As the dehydrogenation catalyst, a catalyst that has been subjected to a reduction treatment as a pretreatment may be used. The reduction treatment can be performed, for example, by holding the dehydrogenation catalyst at 40 to 600 ° C. in an atmosphere of a reducing gas. The holding time may be, for example, 0.05 to 24 hours. The reducing gas may contain, for example, hydrogen, carbon monoxide and the like. By using a dehydrogenation catalyst that has undergone a reduction treatment, the initial induction period of the dehydrogenation reaction can be shortened. The initial induction period refers to a state in which very few of the supported metals in the dehydrogenation catalyst are reduced and in an active state, and the activity of the catalyst is low.

Next, the dehydrogenation step in this embodiment will be described in detail.

The dehydrogenation step is a step in which a raw material gas is brought into contact with a dehydrogenation catalyst to carry out a dehydrogenation reaction of alkanes to obtain a produced gas containing unsaturated hydrocarbons.

The raw material gas contains alkanes. The carbon number of the alkane may be the same as the carbon number of the unsaturated hydrocarbon of interest. The carbon number of the alkane may be, for example, 4 to 10, and may be 4 to 6.

The alkane may be, for example, chain-like or cyclic. Examples of the chain alkane include butane, pentane, hexane, heptane, octane, and decane. More specifically, examples of the linear alkane include n-butane, n-pentane, n-hexane, n-heptane, n-octane, n-decane and the like. Examples of the branched alkane include isobutane, isopentane, 2-methylpentane, 3-methylpentane, 2,3-dimethylpentane, isoheptane, isooctane, and isodecane. Examples of the cyclic alkane include cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, and methylcyclohexane. The raw material gas may contain one kind of alkane, or may contain two or more kinds of alkane.

In the raw material gas, the partial pressure of alkane may be 1.0 MPa or less, 0.1 MPa or less, or 0.01 MPa or less. By reducing the partial pressure of alkanes in the raw material gas, the conversion rate of alkanes can be further improved.

Further, the partial pressure of the alkane in the raw material gas is preferably 0.001 MPa or more, and more preferably 0.005 MPa or more, from the viewpoint of reducing the reactor size with respect to the raw material flow rate.

The raw material gas may further contain an inert gas such as nitrogen or argon, or may further contain steam. By including steam in the raw material gas, the decrease in catalyst activity tends to be remarkably suppressed.

When the raw material gas contains steam, the content of steam is preferably 0.5 times mol or more, more preferably 1.0 times mol or more, and 1.5 times mol or more with respect to alkane. Is more preferable. The content of steam may be, for example, 50 times mol or less, preferably 10 times mol or less, and more preferably 4 times mol or less with respect to alkane.

In addition to the above, the raw material gas may further contain other components such as hydrogen, oxygen, carbon monoxide, carbon dioxide gas, olefins, and diene.

In this embodiment, the produced gas comprises at least one unsaturated hydrocarbon selected from the group consisting of olefins and conjugated diene. The carbon number of the olefin and the conjugated diene may be the same as the carbon number of the alkane, for example, 4 to 10 or 4 to 6.

The produced gas may contain one kind of unsaturated hydrocarbon or may contain two or more kinds of unsaturated hydrocarbons. For example, the produced gas may contain an olefin and a conjugated diene. Examples of the olefin include butene, pentene, hexene, heptene, octene, nonene, decene and the like, and these may be any isomer. Examples of the conjugated diene include 1,3-butadiene, 1,3-pentadiene, isoprene, 1,3-hexadiene, 1,3-heptadiene, 1,3-octadien, 1,3-nonadien, and 1,3-decadien. And so on.

The dehydrogenation step may be carried out, for example, by using a reactor filled with a dehydrogenation catalyst and allowing the raw material gas to flow through the reactor. As the reactor, various reactors used for the gas phase reaction using a solid catalyst can be used. Examples of the reactor include a fixed bed type reactor, a radial flow type reactor, a tube type reactor and the like.

The reaction form of the dehydrogenation reaction may be, for example, a fixed bed type, a moving bed type or a fluidized bed type. Of these, the fixed floor type is preferable from the viewpoint of equipment cost.

The reaction temperature of the dehydrogenation reaction, that is, the temperature inside the reactor may be 300 to 800 ° C. or 500 to 700 ° C. from the viewpoint of reaction efficiency. When the reaction temperature is 500 ° C. or higher, alkanes tend to be more easily converted. When the reaction temperature is 700 ° C. or lower, catalyst deterioration is suppressed and high activity tends to be maintained for a longer period of time.

The reaction pressure, that is, the air pressure in the reactor may be 0.01 to 1 MPa, 0.05 to 0.8 MPa, or 0.1 to 0.5 MPa. When the reaction pressure is in the above range, the dehydrogenation reaction tends to proceed more easily, and a more excellent reaction efficiency tends to be obtained.

When the dehydrogenation step is performed in a continuous reaction format in which the raw material gas is continuously supplied, the weight space velocity (hereinafter referred to as "WHSV") may be 0.1 h ^-1 or more, and may be 1.0 h. It may be ^-1 or more, 100h ^-1 or less, and 30h ^-1 or less. Here, WHSV is a ratio (supply rate / catalyst mass) of the supply rate (supply amount / hour) of the raw material gas to the catalyst mass in the continuous reactor. The amount of the raw material gas and the catalyst used may be appropriately selected in a more preferable range depending on the reaction conditions, the activity of the catalyst, and the like, and the WHSV is not limited to the above range.

In the dehydrogenation step, the reactor may be further filled with a catalyst other than the above-mentioned dehydrogenation catalyst (hereinafter, also referred to as the first dehydrogenation catalyst).

For example, in the present embodiment, a second dehydrogenation catalyst that catalyzes the dehydrogenation reaction from the olefin to the conjugated diene may be further filled after the first dehydrogenation catalyst of the reactor. Since the first dehydrogenation catalyst is excellent in the reaction activity of the dehydrogenation reaction from alkenes to olefins, it is possible to fill the product gas obtained by filling the second dehydrogenation catalyst after the first dehydrogenation catalyst. The proportion of conjugated diene can be increased.

Further, in the dehydrogenation method according to the present embodiment, a production gas containing an olefin obtained in the dehydrogenation step (hereinafter, also referred to as a first production gas) is brought into contact with a second dehydrogenation catalyst to form an olefin. It may further include a step of performing a dehydrogenation reaction to obtain a second produced gas containing a conjugated diene (hereinafter, also referred to as a second dehydrogenation step). According to such a dehydrogenation method, a product gas containing a larger amount of conjugated diene can be obtained.

As the second dehydrogenation catalyst, any catalyst for the dehydrogenation reaction of olefins can be used without particular limitation. For example, as the second dehydrogenation catalyst, a noble metal catalyst, a catalyst containing Fe and K, a catalyst containing Mo and the like can be used.

The conditions of the dehydrogenation reaction in the second dehydrogenation step may be the same as the conditions of the dehydrogenation reaction in the first dehydrogenation step.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the Examples.

[Catalyst synthesis example 1]
<Preparation of catalyst A-1>
A solution A in which 0.101 mL of a dinitrodiamine platinum nitrate solution having a Pt concentration of 100 g / L was diluted with 0.601 mL of water was prepared, 1.0 g of an MgAl _{2 O4} carrier was added to the solution A, and the mixture was kneaded. Then, it was dried overnight in an oven at 130 ° C., and the dried solid was calcined at 550 ° C. for 3 hours under air flow. Next, a solution B in which 66.6 mg of sodium sodium trihydrate was dissolved in 0.689 mL of water was prepared, 1.0 g of the solid after firing was added to the solution B, and the mixture was kneaded. Then, it was dried overnight in an oven at 130 ° C., and the dried solid was calcined at 550 ° C. for 3 hours under air flow. Then, the sodium compound contained in the obtained solid was removed with ion-exchanged water. Finally, hydrogen reduction was carried out at 550 ° C. for 2 hours to obtain a catalyst A-1 carrying Pt and Sn. In the catalyst A-1, the amount of Pt supported was 1.0% by mass, and the amount of Sn supported was 2.6% by mass.

In the ammonia TPD method, the acid amount of A-1 defined by the amount of ammonia desorbed in the temperature range of 200 ° C. to 500 ° C. was 3.31 μmol / g.

[Catalyst synthesis example 2]
<Preparation of catalyst A-2>
ZrO ₂ -CaO carrier (Z-2920, Daiichi Rare Element Chemical Industry Co., Ltd., first metal oxide: 98.2% by mass (ZrO ₂ is about 96% by mass, HfO ₂ ) instead of MgAl ₂ O ₄ carrier. Approximately 2% by mass), a second metal oxide: 1.8% by mass (CaO: 1.8% by mass)), and a solution in which the amount of diluted water was 1.299 mL instead of solution A. The catalyst was prepared in the same manner as in Example 1 of catalyst synthesis, except that the solution B was used and the solution in which the amount of water used for dissolving the sodium trihydrate trihydrate was 1.387 mL was used instead of the solution B. This was done to obtain catalyst A-2. In the obtained catalyst A-2, the amount of Pt and Sn supported was the same as the amount of Pt and Sn supported in the catalyst A-1.

In the ammonia TPD method, the acid amount of the catalyst A-2 defined by the amount of ammonia desorbed in the temperature range of 200 ° C. to 500 ° C. was 7.02 μmol / g.

[Catalyst synthesis example 3]
<Preparation of catalyst A-3>
ZrO ₂ -La ₂ O ₃ carrier (Z-1799, Daiichi Rare Element Chemical Industry Co., Ltd., first metal oxide: 90.9% by mass (ZrO ₂ is about 89% by mass) instead of MgAl ₂ O ₄ carrier , HfO ₂ is about 2% by mass), second metal oxide: 9.1% by mass (La _{2O 3} is 9.1% by mass)), and the amount of diluted water is used instead of solution A. Except for the fact that a solution of 1.105 mL was used and a solution of 1.193 mL of water used for dissolving sodium oxalate trihydrate was used instead of solution B, the catalyst synthesis example 1 and the solution were used. The catalyst was prepared in the same manner to obtain catalyst A-3. In the obtained catalyst A-3, the amount of Pt and Sn supported was the same as the amount of Pt and Sn supported in the catalyst A-1.

In the ammonia TPD method, the acid amount of the catalyst A-3 defined by the amount of ammonia desorbed in the temperature range of 200 ° C. to 500 ° C. was 4.59 μmol / g.

[Catalyst synthesis example 4]
<Preparation of catalyst B-1>
ZrO ₂ -La ₂ O ₃ carrier (Z-3027, Daiichi Rare Elemental Chemical Industry Co., Ltd., Daiichi Metal Oxide: 60.2% by mass (ZrO ₂ is about 58% by mass) instead of MgAl ₂ O ₄ carrier , HfO ₂ is about 2% by mass), second metal oxide: 39.8% by mass (La _{2O 3} is 39.8% by mass)), and the amount of diluted water is used instead of solution A. Except for the fact that a solution of 1.399 mL was used and a solution of 1.487 mL of water used for dissolving the sodium trihydrate trihydrate was used instead of the solution B, the catalyst synthesis example 1 and the solution were used. The catalyst was prepared in the same manner to obtain catalyst B-1. In the obtained catalyst B-1, the amount of Pt and Sn supported was the same as the amount of Pt and Sn supported in the catalyst A-1.

In the ammonia TPD method, the acid amount of the catalyst B-1 defined by the amount of ammonia desorbed in the temperature range of 200 ° C. to 500 ° C. was 2.83 μmol / g.

[Catalyst synthesis example 5]
<Preparation of catalyst B-2>
A TiO ₂ carrier (STR-100N, Sakai Chemical Industry Co., Ltd.) was used instead of the MgAl _{2 O4} carrier, a solution having a diluted water volume of 1.099 mL was used instead of the solution A, and the solution B was used. The catalyst was prepared in the same manner as in Catalyst Synthesis Example 1 except that the solution in which the amount of water used for dissolving the sodium trihydrate trihydrate was 1.187 mL was used instead of the catalyst B-2. Obtained. In the obtained catalyst B-2, the supported amounts of Pt and Sn were the same as the supported amounts of Pt and Sn in the catalyst A-1.

In the ammonia TPD method, the acid amount of the catalyst B-2 defined by the amount of ammonia desorbed in the temperature range of 200 ° C. to 500 ° C. was 2.83 μmol / g.

(Example 1)
A tube-type reactor was filled with 1.0 g of catalyst A-1, and the reaction tube was connected to a fixed-bed flow reactor. Next, the reaction tube was heated to 550 ° C. and kept at the temperature for 2 hours while circulating a mixed gas of hydrogen and N ₂ (hydrogen: N ₂ = 1: 1 (mol ratio)) at 125 mL / min. .. Subsequently, while maintaining the reaction tube at 550 ° C., a mixed gas of N ₂ and steam (water) (N ₂ : steam = 5.3: 3.2 (molar ratio)) was added at 54.5 mL / min for 20 minutes. It was distributed. Then, a mixed gas (raw material gas) of n-butane, _N2 and steam (water) was supplied to the reactor, and the dehydrogenation reaction of n-butane in the raw material gas was carried out. Here, the molar ratio of n-butane, _N2 and steam in the raw material gas was adjusted to 1.0: 5.3: 3.2. The supply rate of the raw material gas to the tubular reactor was adjusted to 60.9 mL / min. The WHSV for the total amount of catalyst was adjusted to 1.0h ^-1 . The pressure of the raw material gas of the tubular reactor was adjusted to atmospheric pressure.

When 60 minutes had passed from the start of the reaction, the product (produced gas) of the dehydrogenation reaction was collected from the tubular reactor. The reaction start time is the time when the supply of the raw material gas is started. The collected produced gas was analyzed using a gas chromatograph (TCD-GC) equipped with a thermal conductivity detector. As a result of the analysis, it was confirmed that the produced gas contained butene and 1,3-butadiene. Based on the above gas chromatograph, the butane concentration (unit: mass%) in the collected produced gas was quantified.

From the butane concentration in the produced gas, the butane conversion rate at the time after 60 minutes was calculated. The butane conversion rate after 60 minutes has passed is defined by the following equation (1).
R ₁ = (1-M ₁ / M ₀ ) x 100 (1)
In the formula (1), R ₁ is the butane conversion rate after 60 minutes, M ₀ is the number of moles of n-butane in the raw material gas, and M ₁ is the generated gas after 60 minutes. The number of moles of n-butane.

As a result of the calculation, the butane conversion rate at the time when 60 minutes had passed from the start of the reaction was 58.0%.

(Example 2)
The dehydrogenation reaction of n-butane and the analysis of the produced gas were carried out by the same operation as in Example 1 except that the catalyst A-2 was used instead of the catalyst A-1. The butane conversion rate 60 minutes after the start of the reaction was 72.4%.

(Example 3)
The dehydrogenation reaction of n-butane and the analysis of the produced gas were carried out by the same operation as in Example 1 except that the catalyst A-3 was used instead of the catalyst A-1. The butane conversion rate 60 minutes after the start of the reaction was 72.4%.

(Comparative Example 1)
The dehydrogenation reaction of n-butane and the analysis of the produced gas were carried out by the same operation as in Example 1 except that the catalyst B-1 was used instead of the catalyst A-1. The butane conversion rate was 50.3% 60 minutes after the start of the reaction.

(Comparative Example 2)
The dehydrogenation reaction of n-butane and the analysis of the produced gas were carried out by the same operation as in Example 1 except that the catalyst B-2 was used instead of the catalyst A-1. The butane conversion rate 60 minutes after the start of the reaction was 19.8%.

The results of Examples 1 to 3 and Comparative Examples 1 and 2 are shown in Table 1.

Claims (7)

A dehydrogenation step is provided in which a raw material gas containing an alkane and steam is brought into contact with a dehydrogenation catalyst to obtain a product gas containing at least one unsaturated hydrocarbon selected from the group consisting of olefins and conjugated diene.
The dehydrogenation catalyst contains a carrier and a supported metal containing tin and platinum supported on the carrier.
A method for producing an unsaturated hydrocarbon, wherein the acid amount of the dehydrogenation catalyst defined by the amount of ammonia desorbed in the temperature range of 200 to 500 ° C. in the ammonia TPD method is 3.00 μmol / g or more and 10 μmol / g or less . .. The production method according to claim 1, wherein the acid amount of the dehydrogenation catalyst is 4.00 μmol / g or more. Claim 1 The carrier contains a first metal oxide containing a Group 4 element and a second metal oxide containing at least one selected from the group consisting of Group 2 elements and lanthanides. Or the manufacturing method according to 2. The production method according to claim 3, wherein the first metal oxide contains at least one selected from the group consisting of ZrO ₂ and HfO ₂ . The production method according to claim 3 or 4, wherein the second metal oxide comprises at least one selected from the group consisting of CaO and La ₂ O ₃ . The production method according to any one of claims 3 to 5, wherein the content of the second metal oxide in the carrier is 10% by mass or less based on the total amount of the carrier. The production method according to any one of claims 1 to 6, wherein the alkane contains butane, the olefin contains butene, and the conjugated diene contains butadiene.